Returning the Favour
by OptimisticLady
Summary: What happens to Katrina Jenkins when she meets Sherlock Holmes? Her life goes spiralling into madness, of course. Then the little game of favours begin. Light Sherlock/OC
1. A Brief Encounter

The violin.

A beautiful instrument, and one that Sherlock Holmes' hands knew far too well. It helped to think, and in this case, he was thinking about the rather ridiculous prospect of love. Specifically, being in love with Irene Adler. He supposed it made sense that anybody who found out about the fact he'd saved her life would think that – but Sherlock was not one to fall victim to that dangerous disadvantage, just like The Woman had.

He supposed that she was lucky his phone had made that rather inappropriate sound when she text him her goodbye. It let her know she wasn't going to die.

Of course, John wouldn't have known about any of that, but that meant Sherlock knew about his flatmate's blatant lie about Irene going into witness protection. He didn't blame John for lying, he was trying not to hurt his feelings. Whatever those were.

He paused for a moment, electing to scribble down the notes of the melody he was composing before finally setting down his violin. He stared out the window, wondering what could be going on in London in the month of January. Were people still celebrating the new year? He wouldn't be surprised if they were, Londoners looked for any excuse to drink despite the prices being ridiculously high for a pint.

It seemed as if his curiosity was high enough to warrant him leaving the flat and going for a walk.

He grabbed his coat and scarf, pulling them on and debating whether or not to call up to John and tell him that he was heading out. Then again, there was a good chance John wasn't even in the flat, and Sherlock wouldn't have noticed if he'd come back anyway.

Once outside 221B, Sherlock walked to the south end of Baker Street and continued walking until he came towards Oxford Street. He checked his watch: it was some time past eleven at night, meaning that the busiest street of London was fairly empty apart from the midweek drinkers and late night workers making their towards tube stations and train stations in an effort to get home.

How wonderfully boring it must be to have a regular job that made you work overtime. There was no way on Earth that Sherlock could do that. The same thing over and over? Ha! As if.

Something caught his attention as he wandered past an alleyway. Noises. Not good noises. He sighed, wondering who could have possibly thought it was a good idea to walk down a darkened alley lit by only one dim street light at this time of night. Man or woman, they were an idiot.

Regardless, it gave him something to do.

He turned left and crept down there, and watched the curious sight before him.

There was a woman in trouble – perhaps a few years younger than he was – but she was holding up her own rather well. Her attacker was about the same height as her, and he had a knife against her throat, holding her in an arm lock too.

"I can feel how blunt that knife is..." the woman told him carefully. "The most damage you'll do is put me in A&E, not kill me – I mean, you've fucked my wrist up enough already... You want the bag that badly? Fine."

She tossed her bag slightly to the right of her, and the minute the man made a move for it, she elbowed him in the stomach so that he doubled over. That was when Sherlock decided to hop in and help.

There was an open skip with a broken shovel in it, and he grabbed that and gave the man a good whack over the head with the spade side of it. He fell to the ground, half conscious, so the woman kicked him in the face and he was out like a light.

In the moment that the woman gathered up her things, Sherlock took the time to survey her.

Long, curly brown hair tied up in a ponytail, tired blue eyes and relatively smart outfit that suggested she worked in an office, but not in one that she liked.

"Cheers for that," she said to Sherlock, and he grunted in response, turning away. The woman scurried after him. "Oi! Not gonna give me an explanation? And shouldn't we call the police?"

"Why should I? I was bored, and you're an idiot. And the police won't do anything, that man is homeless." Sherlock stopped on the main street again, waiting for the woman to catch up with him. "Then again, you don't look like an idiot and you certainly don't act like one. My guess would be that you use that alleyway regularly as a shortcut home."

A half smile appeared on her face as she caught up to him and they carried on walking together. "Huh. Got it in one. Not many people can do that, except..." Now it was her turn to survey him, and Sherlock spotted the recognition in her eyes. "Well, I would say it's a pleasure to make your acquaintance, Mr Holmes, but you wouldn't give me the same courtesy."

"Hmmm. Definitely not an idiot."

She rolled her eyes. "Yeah, I got that. Now. Where we going? My flat's the other direction."

"You said something about your wrist, my flatmate's a doctor. You can put two and two together, yes?"

"I should hope so, considering I work with computers."

Sarcasm. The lowest form of wit. In this case, Sherlock could forgive it, because this woman hadn't tried to punch him yet.

"Katrina Jenkins, by the way," she then said. Sherlock made a huffed noise in response. "Wow, you are quite the arsehole…"

"There it is. Took you longer than other people, but we got there..." he almost seemed amused by that. "You're not from around here, are you?"

"Nope. Would you like to guess where from?"

"I'd say Sheffield."

"Close, but..."

"Chesterfield?"

"Yes. How'd you figure that one out?"

"Your voice holds a hint of an accent on particular words. Not noticeable enough for people to outright think you're not from the South, but noticeable enough to consider the Chameleon Effect."

"Parents decided to move south when I was about eight," Katrina said, as they approached Baker Street.

"I really don't care about the details, Miss Jenkins."

She grimaced. "My boss calls me 'Miss Jenkins,' so Katrina is just fine with me."

Sherlock shrugged as they stepped up to 221B, and unlocked the door. "Formalities. It's um… it's polite, isn't it?"

"Something like that. Not that I care for politeness half the time," she said, following him inside and up the stairs.

"Are you sure about that? You were oddly polite to me."

"You helped me sort of beat up a guy who was attempting to mug me with a blunt knife. I had to be polite," Katrina replied in a matter of fact voice.

Sherlock smirked as he tossed his coat onto the sofa. "John!" he then called out. "We have a client. Sort of..." He turned to Katrina. "Sit there." He pointed at the wooden chair by the desk. Katrina gave him an odd look, but went there anyway.

A few moments later, a jumper clad man came trudging into the room. He looked like he had just been about to go to bed.

"What?" he sighed at Sherlock, who gestured with his head towards Katrina. "Really?"

"I'm assuming she has a sprained wrist, but I'd rather have your… professional opinion."

"So she's not a client?"

"No." Sherlock grabbed his laptop and settled in the blue armchair, pretending to ignore his flatmate and Katrina, but he kept shooting glances at them every now and then while the good doctor fixed up the woman's wrist.

The room was silent, but from every glance Sherlock took at Katrina, he began to learn more and more about her. It took about ten minutes before he cracked and decided to grill her.

"Necklace. Where did you get it from?" he asked her.

"Excuse me?" she jumped, while on her way out.

"Necklace. Tiny diamond, but still too expensive for you to buy on the current wage you earn, although your quite charming two bedroom flat in Brixton says otherwise..."

She didn't even want to know how he knew about that.

"Not that it's actually any of your business, but the flat in Brixton is cheaper than you think, and necklace was a gift from someone I dated a couple of years ago." Katrina turned back to John. "Thank you, Dr Watson."

He smiled. "No trouble at all. Um… see you around?"

"Maybe." Katrina glanced at Sherlock. "Good night, Mr Holmes. I think I owe you a favour now."

And with that, she left.

"Take a night bus, would you?!" Sherlock called after her, but she was gone. He scowled at the empty doorway, while John looked at him oddly.

"How did you find her?" he then asked his friend.

"I went for a walk, someone had a knife to her throat." Sherlock shrugged. "She would have done fine on her own, if I'm honest, but I needed something to do."

"You'll get a case soon, Sherlock..." John said, getting up. "But for Christ's sake, let me sleep."

John left the living room and retreated to his bedroom, leaving Sherlock to mull the woman's last words to him over in his mind.

I think I owe you a favour now.

He groaned, realising that he would most likely run into the damn woman again.

Well, at least his life would be a little more interesting on his off days, now.


	2. The Diamond Girl: Excursions

A few days later, things got rather interesting.

Katrina rarely frequented cafes - in fact, she rarely frequented central London outside working hours, except she had fancied an excursion out - but there was one just off of Oxford Street that took her fancy and she decided that instead of getting a coffee to go, she would sit inside instead. It was fairly quiet inside, and Katrina was certain that this particular coffee shop held a slightly more upper class clientele.

As she waited for her beverage to be made, a newspaper caught her attention on the table nearby. She went and sat down, picking it up and reading what was one the front page: apparently there had been several break ins at flats near Brixton, places completely ransacked and yet nothing was taken.

Her eyes narrowed at that, and she sighed, tossing down the paper onto the little table in front of her. Well, she supposed she would have to be on her guard now.

The coffee was brought over to her by the barista, and Katrina thanked him with a smile before going back to brooding over the potential of her flat being broken into. She wondered how high of a chance that would actually happen. There were a lot of flats in the Brixton area that could be utterly turned over.

The real question was what was the point of it all? The police were being as useless as ever with it.

Life in London was never easy, what with all the angry commuters and airhead tourists – crime just added to the throbbing mess of a city. Admittedly, it did make it more interesting, but at the same time… it was something it could use less of.

She stared at the newspaper, sighed once more, and picked it up yet again. She hadn't brought a book with her, and there was hardly going to be signal on her phone at the back of the cafe. Reading useless news about London it was, then. Katrina sipped slowly on her coffee as she did so – it was rather strong, and still quite hot – but it took her all of about forty minutes to finish, including reading the paper from front to back.

When she pushed her cup aside and folded up the newspaper, getting ready to leave, she nearly jumped out of her skin when she saw someone sitting at the table next to her, staring quite intently. Her shock turned to a scowl when she realised who it was.

"Really?" She stood up, picking up her bag and making her way out of the cafe, with Sherlock Holmes hot on her heels. "How did you know I would be here? You literally met me yesterday?"

"What day is it?" he feigned ignorance.

"It's a Saturday."

"Then it was merely a simple process of deduction. I won't bother explaining it." Sherlock fell into step beside her, and she sighed.

"The other night I got the impression you like explaining things."

"I do, but you're not exactly John Watson, are you? You don't particularly care for it."

She raised an eyebrow at him. "That's because I don't actually know you, therefore I don't care at all."

There was a slight edge to her voice that made Sherlock curious, but he didn't say anything about it. "You're worried about your flat being broken into."

"What gave it away?"

"The way you were reading the newspaper." He completely disregarded the sarcasm in her voice, causing Katrina to roll her eyes.

They crossed the road and made their way towards Oxford Street, causing Sherlock to pull a face. He well and truly hated the busy crowds that wandered the main streets of London on a weekend. Tourists were far too slow and were the bane of his life. Then again, he rarely ever had to deal with them because he got taxis everywhere. Why shouldn't he abandon Katrina and hail one down and go home now?

Oh that was right, because he was going to be polite and accompany her back to her flat, just in case it had broken into.

"I'm actually investigating the break ins," he then said, trying to make conversation that wasn't small talk. "Had a client come in this morning. Trashed flat and nothing taken, which begs the question: what are the intruders looking for?"

"These break ins have been going on for a week, and you're choosing to investigate now?" Katrina was a bit unimpressed, until a sly look crossed her face. "Which begs the question: what made you want to look into it?"

He smirked. "Very good. How could you tell?"

"Because you clearly don't deal with boring – I've seen the blog, I know who you are. Most people in London – no, the United Kingdom – know who you are, and therefore know you don't do boring!" she snapped. "Now get on with it." Her voice had completely lost the edge it had previously, which only made Sherlock frown for a moment.

"Jewelry boxes were the only items in bedrooms that were touched. Other trashed rooms included the living room and bathroom. What do you think?"

"They're looking for jewelry?"

"But what specifically?"

"I wouldn't know!" They came up to Oxford Circus and she descended down the steps to the Underground. "Not my area."

"What is your area?"

"Why are you interested?"

"You're right. I'm not."

Sherlock then stopped at the top of the stairs leading down, causing Katrina to huff and look back at him.

"What now?"

"Perhaps we take a cab back to Brixton?" he suggested.

"Uh, no. Too expensive. It's about two quid to get from here to home – why are you still here?"

The detective stepped down to her level – even though he was a few inches taller than her. "I told you, I'm investigating the break ins. I had a client this morning, oh do keep up."

Another eye roll – gosh, this man really was the cause of them, wasn't he? - and Katrina carried on walking down and to the barriers. She pulled out her Oyster card and tapped it on the reader before heading through. She waited for Sherlock to begrudgingly come through and then they went towards the southbound Victoria line escalator

"The tube is too sweaty," Sherlock remarked, "And I hate it."

"I agree, but it's the best way for me to get about."

"So if you live in Brixton, what are you doing up here on a Saturday?"

"It's a nice cafe, and I was bored. Also kind of pricey so tourists avoid it," she shrugged as they made their way off the escalator and headed onto the platform. "It's fool proof."

"Hmm. Fair."

The train came rushing in and slowed to a halt. They didn't talk for the entire journey back to Brixton, not even on the walk back to Katrina's flat. When they were inside, that was when Sherlock piped up.

"Interesting. The client who came to me this morning lives in this building."

"Perfect, guess I'm getting robbed today." Katrina approached the elevator and called for it. It was a quick lift, to be fair, and came on its way pretty speedily.

"Not necessarily," Sherlock pointed out as the doors open and they stepped inside. Katrina pressed the button for the seventh floor and off they went. In silence. Once again.

Getting to the seventh floor, Katrina went towards flat seventy one and pulled out her keys to unlock the door.

Except it was busted.

The pair glanced at each other, and Sherlock lightly pushed the door open.

Katrina was about to protest him doing that, so he held out his arm signaling for her to be quiet. He then pointed at his ear, indicating for her to listen, and she scrunched up her nose, realising what he was getting at and listening out for whatever was happening somewhere in her flat.

They entered directly into the living room and kitchen area, a hallway coming off of it directly in front of them leading towards her bedroom. The source of the noise was coming from the bedroom, clearly.

Katrina glanced towards the kitchen, then nodded with her head at Sherlock to follow her. She then slowly started to sidle her way towards it, her eyes trained on a door in the wall, and Sherlock realised she was aiming to hide in the pantry. He carefully shut the door behind him and went after Katrina.

She opened the pantry door with a slight creak and shuffled inside, Sherlock squeezing in there after her and struggling to close that door properly. After some moving about, they were able to get comfortable, and Sherlock fished his phone out of his pocket and put on the torch light so that they could actually see each other.

They were in very close proximity, and it was all he could do to not whine about it.

"Well now what?" Katrina hissed. "They're probably trashing my bathroom right about now!"

"It's a bit unfortunate, really," Sherlock replied in an equally low voice. "This isn't random. All these break ins must have been calculated carefully..."

"No kidding!"

"Shh!"

"I'm going to punch you once we get out of here, you understand that, right?"

Sherlock nodded curtly, and Katrina was satisfied with his response.

After that, they waited with bated breath, waiting to hear sounds of the living room being trashed. Except that it never came. Katrina went to speak but Sherlock shook his head at her, so she scowled at him.

Time passed incredibly slowly while they were in there, and Sherlock kept an eye on it on his phone. As soon as fifteen minutes had passed and they had heard nothing, he opened the pantry door and backed out of it into the kitchen.

"Are you going to punch me now?" Sherlock asked, raising an eyebrow at Katrina. She merely shook her head at him as if to say she wasn't actually going to bother, but her obvious annoyance changed to worry and she immediately tackled Sherlock to the floor as a gunshot rang out from down the hallway. They landed in a rather messy heap.

"No, I'm not gonna punch you, but I did just shove you to the floor so that'll have to do for now," Katrina told him, breathless. "Shall we get out of here?"

"Good plan."

She rolled off of Sherlock and crawled along the floor and out the door with him not far behind – when in the safety of the hallway, the detective jumped up and helping Katrina to her feet before pulling her along to the stairs and heading up.

"What the – where are we going?!" Katrina wrestled out of his grip as they ran up to the top floor.

"The roof!" Sherlock called back over his shoulder, causing Katrina to stop in her tracks.

"Excuse me?"

He groaned and stopped too, turning to face her. "Do you fancy dying at the age of twenty eight?"

"Twenty seven, and no, I don't!" Katrina then hurried after him as he continued up two more flights of stairs, coming to a halt at the door that led onto the roof. It was held shut by a chain with a padlock. "Now what?"

The sound of foot steps three floors below caused Sherlock to act quickly, and pulled a small leather pouch from his coat pocket. He pulled out some small, thin lengths of metal and started to pick the lock with ease.

Katrina stated at him, completely dumbfounded.

Before she could say anything, Sherlock was pulling the padlock and chain off the handles and they burst through onto the roof, where he swiftly did everything back up again. Soon enough there came an incessant banging of someone trying to get through.

"Now what?!" Katrina cried. We're stuck on a roof with someone trying to kill us! The only way out is down and I really don't fancy dying at twenty eight, there's still far too many people in this world to-"

She stopped herself from finishing the sentence, and Sherlock quirked an eyebrow at her.

"To what?"

"Oh - never mind!" Katrina waved it off as Sherlock turned his attention back to their escape route.

He spun round in a circle with his fingers to his temples a few times with Katrina watching in curiosity until he stopped suddenly, ran, and jumped over to the next building.

Katrina's jaw dropped.

"Well - come on!"

She took a deep breath, then took a run up and-

There was nothing beneath her feet.

The gap between this building and the next felt way too big.

Somehow, she managed to make it, albeit with a fairly rough landing. Sherlock helped her up once more and off they went, speeding down the fire escape route of the building and once they got onto the street, he hailed down a cab to go back to Baker Street.

* * *

 **Hello!**

 **Yes, I know I could have replaced the chapters but the way I've planned the rewrite means there's going to be more chapters and things got shifted around. Regardless, I hope you enjoy it!**

 **-OL.**


	3. The Diamond Girl: Deductions

"I swear to god, I am never, ever following you on a rooftop again. Next time I'll just take my chances with the scary man with the gun," Katrina told Sherlock as they walked up the stairs into the living room of 221B.

A rather bemused John looked up from his laptop as they entered. "Oh. Hello again."

Katrina gave him a curt nod in response, watching as Sherlock took of his coat and then very abruptly pulled up a chair for her to sit in. She didn't quite catch onto the fact that that was the point of the chair, until he pointed at it while looking at her.

After she sat down, Sherlock made his way to the blue chair, and John made his way to the red. The surveyed her in silence for some time, the detective with his fingers steepled under his chin, before someone actually said anything.

"So… what happened on the rooftop?" John asked carefully.

"Oh!" Sherlock appeared to snap back to reality. "Katrina's flat was broken into about half an hour ago, and I finally have a theory about what they could be looking for."

"Really?"

"Hmm. That." Sherlock once again pointed at Katrina, except more specifically at her neck. She brought a hand up and felt about for her necklace pulling it out from under her collar.

"This? Really? Why? And actually give me a good explanation because I have gone back and forth across London a lot today..."

"Jewelry boxes were the main target of all the break ins, and they kept happening in your area. You said someone gave it to you that diamond necklace as a gift. What happened to him after that?" Sherlock leaned forward, interested in actually listening to what she had to say.

"I - well - we broke up a couple of weeks after that. He blocked me on everything but it was odd because apparently he did that to a lot of people, and…" Katrina made eye contact with Sherlock as she came to realise something. "He didn't do the stereotypical ex thing and block me, did he?"

"Funny how you're only coming to realise that now," Sherlock scoffed, causing John to sigh.

"I'm not one to linger over a break up. I was going to give back the necklace but it's like he didn't exist, it was like… he'd been wiped off the face of the Earth."

"That's because he was. Going by the fact someone is clearly after it, I'd say he was killed for stealing it. Meaning… hm. Someone really wasn't very happy about it. But why now?" Sherlock sank back in his seat, pondering over the length of time since the diamond was stolen and the break ins happening to get it back.

"Whoever wants it back probably wants to use it for something?" John offered. Sherlock glanced at him for a second, actually considering what he said.

"What would someone want to use a diamond for?" asked Katrina.

"It's the hardest known material making it pretty strong and durable, therefore it has the potential to break anything if used correctly," Sherlock reeled off pretty quickly. "Plus, value."

"Great. What would someone want to break into with a diamond?"

"Dunno yet. I'm sure it'll happen soon." He gave her the most fake, wry smile, that she felt a little bit uncomfortable.

"Again - great. I really wish I didn't have anything to do with this."

"Oh, don't we all. I have to say, Katrina, you're really dumbing yourself down, aren't you?" Sherlock said quite suddenly.

"I - what?" The woman in question appeared to be a little shaken.

"Sherlock…" John warned.

"Bad office job that's way under your skill bracket, clothes that haven't been updated in a good four years, and you're constantly on edge. Not to mention you threatened to punch me, but I think that's just scratching the surface…"

"So?" Katrina looked offended.

"So what I'm getting at, Katrina, is what's your deal?" I saw your living room. I know what you can do."

"My deal, huh? I don't think that's any of your business. And as to what you think I can do? Again, find me a job where I can do it and then I'll upgrade my wardrobe to suit myself," she snapped back, her nostrils flaring a little as she said that. "And we're also not going to say a word about what's in my living room."

Silence fell in the room. The two men shared a look - one of surprise - before they looked back at Katrina.

"What?" she asked after a moment, her face showing how weirded out she was by the pair of them looking at her like that.

"Funny. Nobody tells him off," John replied.

"People need to do it more often. Anyway - back to the point - what do I do?"

"We need to do more investigating. We need to actually confirm that whoever it is is actually after you," piped up Sherlock again.

"Are - are you saying I need to wait until somebody tries to come after me again?"

"Precisely. Good, I'm glad you're catching on," Sherlock nodded, and Katrina facepalmed.

"Alright, fine. I guess I should head home now, yeah? I can find your number on your website," she told him, rising from the chair and smoothing out her coat in the process. Sherlock frowned at that last remark.

"No you can't, it's not on my website."

Katrina smirked. "Yeah, I was just saying that. I'll find it. Don't you worry. I'll let you know if anything happens."

"Good day, Katrina," Sherlock muttered as she left.

When she got out of 221B, Katrina felt as if she could breathe again, letting out a heavy sigh. So the past day had gone from relatively normal to outlandish within the space of a couple of hours - not to mention she needed to clean up her trashed flat - and of course, there was the chance that someone was out to kill her for a tiny diamond sitting on her neck.

Speaking of, Katrina hastily tucked that back into her shirt, and made her way to the tube station at the end of Baker Street.

As she was slowly making her way down the escalator, she popped her earphones in and put on some music in an effort to keep level headed about the situation. She head to the southbound platform for the Bakerloo Line and sat down at one of the few seats, waiting for a train to come.

She noticed someone hover nearby, but didn't think much of it because it was a Saturday in London after all, probably just some tourist. Nobody knew the concept of personal space on the Underground.

A few moments later, the train arrived and she got on, electing to stand rather than sit considering she would be changing to the Victoria line at Oxford Circus for the second time that day to get back to Brixton.

On the walk through Oxford Circus, she could feel someone walking a little too close to her. Now that was beyond the idea of no personal space. She lightly elbowed whoever it was and quickened her pace, managing to hop onto her next train just before the doors closed. As did someone else, and they went crashing right into her.

"Jesus - mind out, would you?!" Katrina batted the man away from her before going to sit down. As she looked back over at him, he shook his head and went to go sit down himself.

She turned her music up and kept trying to sneak glances at the man, but to no avail since more people appeared to get on the tube at Green Park. Something seemed off. Katrina could feel it.

Eventually she got back to Brixton for the second time that day, and feeling eyes on her, Katrina glanced back over her shoulder while walking in the direction of her home - towards the Brixton Academy - that the same man from the tube was close by, watching her. Ripping out of her earphones, Katrina hurried on down the street and made her way back to her flat, keeping as alert as possible at all times.

She could have been paranoid, but at the same time it was no mere coincidence that it was happening on today of all days.

Heading back into her rather trashed flat (now with an added gunshot in the door), Katrina slammed the door and dived straight for one of her many laptops on the sofa. She needed to find Sherlock's number, and right now.

It didn't take very long to find. Too easy.

She whipped out her own mobile phone and shot him text.

 _Was followed to Brixton. Probably being watched.  
_ _-K. A. Jenkins_

 _Alright.  
_ _-SH_

 _Also, you were quick on getting my number.  
_ _-SH_

 _That's about as much of a compliment you will get._  
 _-SH_

Despite everything, a small smile came to Katrina's face. Small victories were worth something. She wasn't trying to impress him by any means but damn, the validation was good, as annoying as he was.

* * *

 **I've planned this out So Well, I believe. Probably the most excited I've been for a rewrite!**

 **Do leave a comment, means the world!**

 **-OL.**


	4. The Diamond Girl: Detective Work

Sherlock had been lying on the sofa, his jacket and shoes removed with his eyes shut in what seemed to be deep thought when his phone vibrated. A half smile appeared on his face as he saw the text was from Katrina, and he checked his watch.

"Thirty seven minutes to get to her flat from here, and another six to get my number…" he murmured as he replied to her.

"What was that?" John asked from the desk, and Sherlock jumped up, heading over and pulling out a map of London and spreading it out right before his friend.

"It takes thirty six minutes to get from here," he pointed at the location of their flat on Baker Street, "to here, via the tube and walking for a bit," he pointed at the general location of where Katrina's flat was in Brixton.

"And?"

Sherlock blinked. "Well, it took her another six minutes for her to get my phone number."

"About that - how?" John finally turned away from his laptop to give his full attention to Sherlock.

"...Google?" The detective replied after a moment.

"Sherlock…"

"She's very good with computers."

"Have you even put your number online?"

"Nope. Just my email."

"I see."

"Really?" Sherlock frowned.

"No."

"I have a feeling that if you gave Katrina the opportunity to do so, she could hack anything she wanted," Sherlock explained.

John laughed. "Nooo."

Sherlock's face said it all, and John became rather serious.

"She can't."

"She can. Her living room has a nice little collection of disassembled laptops and what I suspect to be stolen bits of hardware that let her do what she wants," he paused. "I wouldn't be surprised if she's watching us through your webcam right now."

Now it was John's turn to jump up from his seat and back away from his laptop.

"Don't be too alarmed," Sherlock said. "If She is watching us - I doubt she is, she's probably clearing up her flat right now - but if she is… she'll have to be wary of Mycroft."

"Because it would be… very illegal for her to do that."

"Yes. Katrina is more clever than she lets on. Oh!" Sherlock grabbed his phone, and sent another text to the woman in question.

 _What did he look like?  
_ _-SH_

 _Tall, black hair, kind of cute I guess.  
_ _-K. A. Jenkins_

Sherlock groaned and tossed his phone back onto the sofa. John watched with a bemused expression. The detective began muttering to himself, something along the lines of "of course she thought he looked cute but that doesn't help me," until John cleared his throat. Sherlock stopped in his tracks.

"Well?" The Good Doctor folded his arms.

"We need to get hold of the tube footage from the past hour. Unfortunately that means going to see Lestrade, and it'll have to wait until Monday."

"So now what? We do nothing?"

"Exactly that. Tea?"

John frowned. Sherlock never offered tea. "Are you alright?"

"I'm trying to pass the time," he said, wandering into the kitchen. "Lestrade is back in on Monday - everyone else down at the Yard are idiots."

He was practically seething at that last part as he flipped the switch on the kettle. Even though Lestrade wasn't exactly the greatest detective on earth, he was the most bearable. It would be a lot quicker if Lestrade was about.

Sherlock opted for the container of coffee rather than the jar of tea bags, putting a heaped teaspoon of the instant powder into his mug, along with two teaspoons of sugar. The idea of making John a tea was completely forgotten as he poured the finally boiled water into the cup.

He proceeded to his room, slamming the door in the process.

The next two days were going to be painfully boring.

For the most part, Sherlock sulked, and not even John could coax him out of his bedroom. No matter how much knocking or offering of tea, it was near impossible to get Sherlock out.

It got to the point on Sunday evening where John pounded on the door.

"Sherlock for god's sake! You're meeting Lestrade tomorrow so buck up!" he yelled.

There was some movement from the other side of the door, and the next thing John saw was Sherlock glaring at him, a little unkempt and tired looking, but wearing his best dressing gown over the top of his regular clothes.

"I've been thinking," the detective said, pushing past and out towards the living room, where he promptly began pacing.

"Of course you have…" John muttered, following him into the living room. "Care to enlighten?"

"Why now? Why would someone want the diamond back now after it's been missing for at least 3 years?" Sherlock's fingers were steepled under his chin as he walked up and down the room.

"Well… you said yourself that diamond is the hardest material…" John leaned against the kitchen doorway, crossing his arms.

"And? Please tell me there was more to that train of thought because that piece of information has been bugging me all last night and all of today!"

"You can only cut diamond with diamond."

That made Sherlock stop in his tracks, and he turned to his friend slowly.

"Say that again."

"Uhm," John cleared his throat, "You can only cut diamond… with… diamond?" After a moment of looking confused, it clicked for him too. "Wait - you don't honestly think someone wants to use a diamond to break in somewhere?!"

"It would be like slicing through softened butter," Sherlock mused. "It's unfortunate we don't know who wants it or for when - something like this is easily preventable."

"Really?"

"If I were actually working for Scotland Yard, yes."

"Right, right… Anything else?"

"Hmm, not until tomorrow, no."

"Okay. Are you going to stop sulking?"

Sherlock raised an eyebrow, which told John everything he needed to know.

While the detective stayed in the living room, occasionally pacing and stopping to look out the window, John headed upstairs and went to bed.

* * *

"Why didn't you come in on Saturday then?" Lestrade asked as they walked to Baker Street underground. "Could have got this done a lot quicker."

"You weren't in, therefore I didn't want to have to deal with an idiot," Sherlock replied, hands in his pockets as they headed into the station and over to the booth window.

"How can I help you today?" the person inside the booth clearly did not want to be at work. Lestrade took out his wallet and flashed his ID, making the clerk's eyes widen. "What can I do for you, Inspector?"

"We need to have a look at security footage from Saturday," Lestrade told him. "Is there anyone who's a bit higher up that can we can talk to for that?"

"Um, yeah, I'll just—"

The lad wandered off to the back of the room and through a door, coming out a different one next to Sherlock, John, and Lestrade, with who appeared to be the manager in tow.

"If you would like to follow me to my office, we can go through Saturday's footage in privacy there," she said with a gentle smile.

The group followed the woman through and after squeezing into the fairly cramped office around her desk, a security guard came back with a USB drive that she plugged into her computer.

Sherlock took charge at that point, finding the exact time Katrina entered Baker Street tune station, and keeping an eye out for anyone who was particularly keen in catching up with her.

"There!" Sherlock paused the movie and pointed at a person on the screen. "Matches her description." He turned to Lestrade. "If you take this, can you find out who he is and what he's doing?"

"Can all be with you by the end of the day," the inspector agreed. He took the mouse from Sherlock and closed everything on the computer, taking the USB out of it too. "Sorry for being so vague about this, Miss," he addressed the woman in charge of the tube station, "but it's important we do this quickly or someone could get hurt."

"Murdered," Sherlock corrected, causing John to sigh. "Katrina could get murdered if she's not careful. Good day."

He rose and left the office with difficulty, John and Lestrade muttering apologies to the manager and going after him.

"The sooner you get this to me, the sooner I can let Katrina know, and do my own research. There's more to this than you think, Lestrade, and you are most definitely out of your depth."

* * *

About two hours later, Sherlock's phone pinged. As he glanced down at it, a half smile formed on his face.

Lestrade had the person, and was emailing everything over to him. Probably wasn't meant to do that, but he knew Sherlock wasn't likely to go all the way down to the Yard.

Jumping off the sofa and going to the desk, Sherlock opened up his laptop and accessed the email, flipping through the PDF document that had been sent to him. He grinned.

This case just got a whole lot better.

* * *

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	5. The Diamond Girl: Pub

Thursday nights at her workplace usually meant drinks. Sometimes there was a reason, other times there was no reason at all. They all just had to be careful not to drink too much and get a hangover the next day. As to why they didn't drink on a Friday? Everything in London was more expensive on a Friday. Thursday night was still the cheap night in all pubs, clubs, and bars.

So Katrina thanked her lucky stars as she sipped on her second double Jack and coke of the night that Thursday nights existed. She was sat at a table with the rest of the tech department, having a jolly old chat and bitch about their workplace and how they were treated.

"...Meanwhile you've got Kat who is the most _ridiculously_ underpaid of us all!" said Ollie, one of the tech runners. She nearly choked on her drink.

"Excuse me?!"

"Come on, Kat, we all know you're way better than what you're paid. If anything, you should be in charge of the whole department."

"Hmm, Head of IT at a film company? I think I might pass, thanks very much. Besides, Lucas is doing a pretty good job of it…"

"Yeah, even I think you're being shafted," said Lucas, and Katrina pouted. "Come on now, you should really talk to HR about getting a pay rise."

"Which I can't do until September when my annual review is," she pointed out. "We're still in January, come on now."

Lucas shook his head in disappointment, chugging back some of his beer.

"Besides," Katrina carried on, straightening up in her seat a little. "I don't particularly want to draw any attention to myself. And I'd get too angry at all the stupid requests people put in."

Ollie raised an eyebrow. "You do that anyway."

Katrina shrugged while the rest of the table laughed, and she couldn't help but have a little chuckle herself. The people she worked with were good people, and even though she wasn't a fan of her job and knew she should be higher up, she was still fine where she was.

At least they knew it, too.

A clink and a light plop brought Katrina out of her thoughts.

She looked down into her tumbler and frowned.

"Did - did you just penny me?" She directed the question at Ollie.

He held up his hands in surrender. "Guilty as charged."

"I haven't been pennied since-"

"Since I did my masters," the entire table finished for her.

"Right, Andy wins. Not even eight thirty…" Lucas said, so he and five others all tossed a tenner each down the table to the man in question, who raked it up quite happily.

"Seriously? You took bets on that? I mentioned it _one_ time!" Katrina said, affronted, as she pulled the penny out of her glass and downed her drink. "Now I need another one…"

She got up and headed over to the bar, ordering her third whiskey and coke of the evening. While she was waiting, she casually glanced around the pub and saw something she was not expecting. When she was handed her drink, Katrina gripped it a little too tightly as she wandered over to the back corner to find Sherlock sitting there with an untouched pint.

"Are you stalking me now, is that what this is?"

"Ah! Katrina," Sherlock threw her a very fake smile to match the fake cheer in his voice. "Didn't expect to see you here." He took a sip of the beer and made a face. Not much of a drinker then.

"That's a lie."

"Correct. I had to find out where you went on Thursday nights. Care to join?"

Katrina glanced over her shoulder at her colleagues, who seemed not to have noticed her disappearance yet - if they had, they were used to it by now - and sat the opposite side of the booth to Sherlock. There was a folder on the table, which he pushed towards her.

She set down her drink and was about to flip through it when-

"What — the hell?!"

Sherlock and Katrina both jumped as John appeared next to the booth, clearly out of breath.

"What are you… you just… ran off…" he sat next to Katrina and took note of the pint. "Do you want that?"

"Not particularly, I only bought it to blend in," Sherlock replied.

"Good." John took the drink and downed at least half of it before he was satisfied.

"Good evening to you too," Katrina said, finally opening the file. She faltered for a moment. "Sherlock?"

"Yes?"

"Why is this in _binary_?"

There was an awkward moment of silence where Sherlock attempted to come up with an excuse, but Katrina got there first.

"You _have_ been stalking me!"

"You didn't reply to my texts!"

"Yeah well, I've been- um..."

He raised a questioning eyebrow at her, while John started on the pint again as he watched.

"Busy," Katrina finished lamely.

"I know."

She shut the file and tossed it back at the detective, folding her arms and grumbling.

"You had a binary print up in your living room, so I wanted to entertain the fact that you knew it. Not to mention the information in here is extremely sensitive," Sherlock said quickly.

"Go on."

"Sebastian Moran is the man after you, and to put it frankly if you don't hand the necklace over, he _will_ kill you."

"Who does he work for?"

"The highest paying person."

"And who's that?"

"I don't know. Some things slip under the police radar, and even doing my own research I couldn't find out." Sherlock seemed put out by that but if information.

"Are we going to play a game of sitting ducks so that we can find out?"

"No, we're going to play a game of favours, actually."

Katrina folded her arms and leaned forward, intrigued. John groaned and downed the rest of the pint.

"Oh?"

"Technically speaking you're a client of mine, but an unwilling one. I'll let you off with not paying if you owe me a favour," Sherlock proposed.

"And if the favour I do for you is so big that you might end up owing me…?"

"That's why it's called a game."

"Right."

She considered it for a moment before offering out her hand for him to shake, which he did, albeit rather bemused.

"That was… easier than I thought it it as going to be," he commented. Katrina shrugged.

"I need some form of entertainment, even if it could be a bit dangerous."

"Katrina, your life is at risk here," John pointed out. "This isn't just a form of entertainment - Sherlock, don't start something like this!"

"His life is on the line here too, depending on how this favour thing goes," she replied. "John, it'll be fine. All we needed to do is find out who Moran works for, hand him the diamond, and bish-bash-bosh we're done and dusted with the whole thing. Simple."

"Not - not quite that simple…" Sherlock murmured. "But you do make a good point about handing over the diamond - if you're willing to part with it, why keep hold of it all this time?"

"Because I could get killed if I don't. There's a reason I have a degree - I'm clever and I can think."

"...Point taken. Seriously though, no emotional attachment to it?"

"I thought the guy who gave it to me was ghosting me when he disappeared off the face of the earth, it was the least he could do. Consider it compensation for what I went through."

Katrina was so blasé that it made both men frown - how often had she dealt with break ups?

"You staying here for the rest of the night?" John asked.

She got out her phone and checked the time. "I'll stay for another half hour and then head home. Why?"

"No reason. Be careful on your way home, especially if he followed you last time."

"Well, I've been fine the past few nights John, but thank you for the concern. Really. Now, I should get back to my colleagues…"

On that note, John moved out of the booth so that Katrina could get out. He sat directly opposite Sherlock after that, who was clearly deep in thought. There was delicate knot to his brow and his eyes were twinkling and alert as he slyly watched Katrina go back over to her table.

"When she leaves, so do we," Sherlock told John quietly.

The doctor looked at him strangely for a moment, before understanding crossed his face. "Gotcha."

* * *

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	6. The Diamond Girl: Moran

Around about nine o'clock and feeling delightfully buzzed, Katrina and her colleagues decided to call it a night and all head home. Some drank more than others, but because tomorrow was a Friday, any potential headaches in the morning weren't going to be a problem. Fridays were often slow because nobody cared enough about their computers or their work by the end of the week - deadline depending.

The tube ride home felt a little more wobbly than usual, and Katrina had to fight to not have a tipsy doze, so instead put on some loud music in her earphones until she reached Brixton. If anything, the warmth of the London Underground has made her feel more out of it, but the whack of cold fresh air upon leaving the station brought her back again.

Katrina walked home quickly, the idea of a glass of water and going to bed calling to her like no other. In preparation for getting to bed efficiently, she put her earphones and phone in her coat pocket upon reaching her building.

The moment she stepped into the warm building, she became properly sleepy againa and struggled to put the key in the lock of her front door, after a good thirty seconds she stumbled inside.

Switching on the light, Katrina dumped her coat and bag in the living room before going to get herself a glass of water. She downed that fairly quickly, and headed back into the living room, pulling off her jumper and her shoes.

She went over to the window and opened it. Even though it was January, she needed to cool off from the tube and brisk walk home. She unbuttoned her shirt, peeling it off and feeling much better in her tank top - the cool air swept over her skin and relieved it from the sweaty heat of her clothes.

Katrina stayed by the window, leaning against the wall next to it, shutting her eyes and taking a moment to make sure the room didn't start to wobble. Perhaps she was more than a little bit tipsy. Perhaps she was drunk.

She was crudely dragged from her thoughts by someone slamming her to the floor by her neck.

Now that sobered her up.

Katrina scrabbled and kicked at the man who had somehow gotten into her flat, managing to get him to loosen his grip on her as she gave him a good whack to the knee. She managed to roll so that she was on top of him, and gave the man a good punch to the face before realising who it was.

Of course, it wouldn't be anyone else other than Sebastian Moran.

Her momentary lapse of attention meant that Moran had a chance and he shoved her off of him and into the coffee table. Luckily it was only a wooden one so didn't break into pieces, but instead tip over with Katrina going over the top of it and whacking the back of her head on the corner of the television stand.

Concusses and woozy, Katrina couldn't react fast enough when Moran took his belt off and promptly wrapped it tight around her throat. She flailed, trying her best to bat him away and then deciding it was probably better to try and hook her fingers under the belt while she was still conscious.

Her face was throbbing as she lost oxygen, and on the cusp of blacking out, Katrina saw her front door slam open - it was Sherlock and John.

Immediately Moran let go of her, and smash to her right told her he had jumped out the window; a resounding crash and an alarm told her he had landed on a car.

She leaned on her elbow, coughing and breathing deeply as she was able to breathe again. Her head was pounding, and fingers on the back of it let her know that John was looking for the damage.

That made her regain her focus, and she jumped up away from him, wobbling slightly so she rested against the wall for support.

"Why - why are you here?" she asked them, but John winced. She'd raised her voice without realising.

"We followed you home," Sherlock responded calmly.

"Why?" Katrina was getting louder.

"I saw him outside the pub."

Breathing heavily and shaking, Katrina dropped to the floor and pulled something out from under the sofa - a laptop. She opened it and began furiously typing in silence.

"What are you doing?" John asked.

"Finding out who he's working for," she said, her voice back at a normal pitch but raspy. "You should have just left me to do this…"

"Katrina, you need to go to A&E…"

"John," Sherlock warned, coming towards his friend and pulling him back from the woman.

"No, she needs to-"

"Who's Jim Moriarty?" Katrina then piped up. The two men looked down at her, surprised. "What?" She stood up again, swaying like before.

"He's… where did you…?" Sherlock's brow knotted.

"That's who Moran works for. So tell me. Who is he? There's not much about him on there except that he worked in IT for a bit."

They still didn't respond, and Katrina's shaking only got worse. She leaned against the wall again, her teeth chattering. She clenched her jaw, trying to stop it, but that only seemed to make her whole head vibrate.

She didn't feel good, that much she knew. Katrina did her best to focus on the two men in front of her - what the hell was going on with her? - and then like a light switch, her brain decided it was time for a little sleep...

…And a couple of minutes later, she came to - John was tapping her face, trying to rouse her. She shoved him away and sat up.

"A&E?" John suggested again, albeit with a more forceful tone. Katrina still shook her head, and he sighed. "You're in shock!"

"No kidding," Katrina groaned, and then using John's shoulder as support, stood up. She was completely out of it, and swayed towards Sherlock who helped to steady her. "I'm not staying here tonight. Get me a cab to a hotel?"

"Uh - no," John said before Sherlock could even say anything. "If you're staying anywhere, it's with us."

The detective rolled his eyes and let go of Katrina, meaning she turned to the other man for support instead. "Not happening," he said, grabbing the woman's coat and bag before making his way out of the flat.

Putting his arm around Katrina's waist, and making sure she was holding onto him, the pair started following after Sherlock. It was surprising how steady on her feet she was, all things considered. They managed to catch the lift before the detective departed in it, and they all went down and out of the building in an awkward silence.

Walking to the main road, Katrina stumbled on the odd occasion, causing Sherlock to get frustrated and help John with her. When they got to the busy road, he used his free arm to hail down a cab, and they three of them got in.

"Just for tonight, and not again," Sherlock told the other two abruptly. "She can sleep on the sofa."

Katrina was taken aback. "Cheers, I guess… Guess I still owe you then."

After that, she slumped with her head falling onto John's shoulder as they set off for Baker Street, the two men exchanging a look as they both wondered what the hell was going to happen now.

* * *

 **Sorry this is a shorter one, but I didn't want to drag it out too much! Things should pick up again next chapter, and I'm aiming to have this updated weekly if I can. Time depending tbh.**

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	7. The Diamond Girl: Bugged

Back at 221B, the men made sure Katrina was as comfortable as possible on the sofa, and gave her painkillers, water, blankets - the lot. John wasn't entirely keen on letting her ride out her injuries without going to A&E, but the woman was still rather insistent on staying there. She absolutely refused to go to a hospital, because she didn't particularly fancy explaining how she got into her plight in the first place.

After an annoying amount of back and forth to which Sherlock ended up having to put a stop to, surprisingly, John retired to his bedroom upstairs, leaving the detective with Katrina. He eyed her curiously from his armchair, uncertain about what the correct social protocol was to a situation like this.

"Will you go into work tomorrow?" he asked her. Katrina rolled onto her side so that she could face him.

"No. Currently my body is protesting against everything I want to do, and I think it's gonna be worse in the morning."

"Fine."

"Have you got a problem with that? Sorry, but I thought I was going to die tonight and I didn't want to stay in my own home. I couldn't stay there."

"We could have taken you to a hotel as you asked." Sherlock shrugged and stood up, making Katrina scoff and roll her eyes. "But since you wouldn't go to A&E, John was your next best bet."

"Whatever then. Good night, Sherlock."

He gave hurt a curt nod before making his way through the kitchen to his bedroom, shutting the door as quietly as possible when he got there.

The detective sat down on the bed and mulled over the evening's events. Everything was beginning to fall into place, he had reason to believe - the only thing that didn't make sense was Moriarty. Why would somebody steal from him? Why did he want it back so badly? Surely if a criminal such as him had an empire of sorts, what need did he have for such a tiny diamond? Sherlock thought it would have been an inconsequential item to the napoleon of crime, but apparently not.

Odd how the man himself was willing to have an assassin kill someone for it. It didn't seem like Moriarty - he liked to play games - unless of course this was just part of a long game that Sherlock couldn't see all the players for yet. Unless Katrina was now going to be a player. Who knew?

The detective snapped out of his thoughts for a moment as he realised that tomorrow he and John were going to have to explain Moriarty to Katrina, as she had practically demanded them to do so earlier on. The fact that she was able to find out a piece of information like that so quickly was… useful, to say the least, as well as dangerous.

Sherlock had no doubt in his mind that at some point Mycroft would come calling about this, and was surprised he hadn't already tried. Although thinking about Big Brother would ultimately summon him, so Sherlock was not going to wait in anticipation until he popped up.

Goodness, the urge to play the violin was rather strong right now, but he knew that he couldn't exactly do that. John was used it, Katrina would not appreciate it in the slightest and may ultimately fly off the handle at him. He wasn't in the mood for that, if he was honest. Sherlock already disliked the idea of Katrina being on their sofa for the night, and disliked the idea of her being pissed off even more.

He sighed and kicked off his shoes and shrugged off his jacket, opting to lie down on top of his bed. There was no telling if Sherlock would sleep tonight, not with the amount running through his head at this current moment in time. He did shit his eyes in an attempt to calm the cogs in his head, and admittedly it did help - how much it would help, he didn't know.

Half asleep and half awake, Sherlock was able to rest at the very least.

He must have drifted off at some point, because something woke him up - the sound on someone vomiting at about eight in the morning. Sherlock sighed deeply, knowing it was Katrina. It was probably to do with her injuries, and that didn't shock him.

Soon enough the sounds subsided and he sat up, listening to the woman wash out her mouth then go potter about in the kitchen hunting for a glass, and apparently the bread. He heard the toaster go off a few minutes later, so he decided to go and investigate properly.

Sherlock found Katrina on the sofa nibbling at a slice of toast with the glass of water by her feet. She looked rough - purple bruising decorating her neck and jaw, and she was unable to hold her head up properly as if it were too heavy. Must have been quite a whack.

"I've already called in sick. Told the HR lady I got jumped on my way home, and now everyone in the department is texting me… I'm ignoring it for the time being," she told him. "I need answers from you and John first, and we're going to figure out what to do."

"That was the plan." Sherlock gave her a look that suggested she was being stupid. "Do keep your vomiting down next time."

"Apologies, your highness," Katrina replied sarcastically.

"That would be my brother…" he muttered. She frowned, but didn't question it and carried on eating. A few moments later, John came into the living room fully dressed and his hair still damp.

"How are you feeling this morning?" he asked,

"I threw up." Katrina set the plate down on the coffee table so she could have some of her water. "Standing up wasn't the best idea this morning… I'll be alright. Now… neither of you answered my question last night."

"Straight to it, I guess…" Sherlock said, sitting in the blue armchair while John went to the red one.

"Who's Jim Moriarty? Not much came up on him, but it didn't look good."

Sherlock sighed. "Quite possibly the most clever criminal to ever exist. He's bad news, and it's even worse for you if he's trying kill you."

"How about we avoid that and give him back the diamond?"

"We have to draw him out."

"He has an assassin after me, I think he's getting close to being drawn out from wherever he's lurking." Katrina went back to munching on her toast after that.

"Then what do you propose?" Sherlock raised an eyebrow at her.

"Nothing. I have a question for you: what are the chances that he'd contact me because I've managed to evade Moran twice now?" she countered.

The detective frowned. "Quite high… but how would he get in contact with you?"

"For a start, I have a twitter. Secondly, Moran's been to my flat twice. Bets I've been bugged?"

"Oh - oh, of course! He'd want you to notice that wouldn't he?" Sherlock was beginning to get quite excited, much to the chagrin of John who couldn't help but take a deep breath. Katrina seemed to be into it, on the other hand, and grabbed her coat from the other end of the sofa, slipping her hand into the pocket. Lo and behold, she pulled out a tiny wireless microphone.

"How? Just _how_ could you know that he'd bug you?" John was shocked, to say the least.

"You know, this is kinda fun. I'm not about the fact I could get killed for a diamond, but bouncing ideas off of you is great," Katrina remarked. "Think I should say my phone number out loud?"

"Please do," Sherlock smirked, and John looked between the pair thoroughly confused.

"Is this foreplay for clever people?!" he cried out before Katrina could even speak. She ignored him as did Sherlock, and proceeded to say her mobile number out loud before crushing the mic with a heavy book on the coffee table.

About two minutes later her phone rang and she happily picked it up.

"I shouldn't be this excited to talk to the man who currently wants to kill me, but considering how I managed to figure out you bugged me, I have to say that you are incredibly over the top," she said.

"Ah. Katrina Ann Jenkins. Pleasure to finally talk. You have something of mine, don't you?"

"Ooh. Irish. I do indeed. Would you like it back? I'd rather be rid of it so I don't get killed."

"Hmmm. Yes please," he sounded far too flirtatious to be acceptable, and Katrina made a fake gagging motion.

"When and where?"

"I'll text you the details, don't particularly want to risk the boys overhearing. If they come, I'll get Moran to shoot you! Ta ta!"

He hung up, and Katrina pocketed her phone appearing thoroughly bemused and concerned at the same time. Sherlock and John were looking at her rather expectantly.

"He's going to text me the details because he doesn't want you two knowing," she said after a moment.

"Did he threaten to shoot you?" Sherlock asked.

"Yep. I trust you'll both follow me to wherever I need to meet him regardless?"

"Yeah, we're not gonna let you go near Moriarty alone," John pointed out.

"Slightly patronising way of putting it, but I get what you mean." Katrina went back to her water after that, wincing as she drank it. Her head still hurt like hell, and the doctor in the room knew it too. "Got anything stronger than ibuprofen, Dr. Watson?" she turned her attention to him.

"My god, you're a walking disaster, aren't you?" was all he could say in response. "Perfect to be hanging out with that one over there." He shook his head and rose, making his way into the kitchen, leaving Katrina frowning after him.

"I take it that's a no then?"

"Don't mind him, he just wishes you'd gone to A&E," Sherlock said. "He's gone to get you an ice pack."

He was right about that, because John came and rudely tossed it at Katrina who just about managed to catch it and place it to the back of her head. She sighed in relief - the coolness of it felt good. Her phone then buzzed, and the two men stared at her.

"That'll be my appointment with death," she muttered. "I'll have a look later, because I really want to vomit again and I really think I should have gone to A&E."

John looked like he was about to lose the will to live.

"What makes you say that?"

"I think there's blood on the back of my head. It's also throbbing."

"How are you a functioning adult?" he sighed, going to get his shoes and coat. "Come on."

* * *

 **Trying to get into a rhythm/schedule of updating this! Thanks for the favourites/follows as well.**

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	8. The Diamond Girl: Conclusion

One long trip to A&E later, Katrina was looking to be in better shape, and she felt much better. There was no permanent damage to her head, although the attending doctor wasn't exactly pleased about the fact she left it so long after the initial incident. The cab journey back to Baker Street involved a lot of "I did tell you" from John, which didn't exactly help. Katrina had to bite back her tongue from snapping at him.

Upon entering the flat again, Sherlock found their bickering somewhat amusing - she was about as stubborn as someone could get. Never wanted help from anyone and would rather do everything herself. Sounded a little bit like him, if he thought about that fact hard enough.

Naturally, the first thing that happened when everyone was back together in the flat was the kettle being put on. Katrina did that - as if it was some odd way of saying "thank you" to the men for helping her out, which they could understand. For some time they sat in silence in the living room drinking the rather nice cups of tea she had made them.

Eventually, the silence was broken. Sherlock began tapping his foot impatiently and Katrina knew he wanted to ask about what Moriarty had text her. She and John glanced at each other, trying to ignore the annoying sound coming from the detective's foot, but it was becoming harder and harder to with each passing second.

Katrina went to the desk and found a spare bit of paper as well as a pen. She started scrawling something down before handing it to Sherlock.

He took it rather excitedly, and scanned through what she had written quite eagerly, pleased with something to get to work on. He was about to speak, but Katrina pressed a finger to her lips. She gestured to be given the piece of paper back so that she could give it to John as well, who nodded in understanding after reading it.

The men looked at Katrina, waiting for her to either say something or give them more information. Instead, she perched herself on top of the desk, thinking for a moment.

"You'll have to be at least fifteen minutes behind me," she said, making them jump. "We can't let him know that you guys know."

"He'll figure it out - he's as clever as I am, sometimes a step ahead of me," Sherlock spat, hating to admit something like that. Katrina rolled her eyes - now wasn't the time to be pissy about something like that.

"Listen, you, we have to do this carefully and my way. Well… his way. I don't fancy having a bullet put in me just because of your ego," she snapped. "Don't be a fool, Sherlock. Don't let your ego get in the fucking way of my life."

"Are you sure you won't get a bullet put in you because of that temper you try so _very hard to suppress_ every day of the week?"

John winced at that.

Katrina's face turned incredibly stony. Her nostrils flared and within a second she had launched herself towards him and grabbed his jacket lapels, pulling him up off the chair. She brought him nose to nose with her, seething.

"Is this what you want? You want to see my temper? Well, here's some of it, Mr Holmes. I really don't give a damn about how clever you think you are, and that you have the ability to figure out who I am with one glance, but there are some lines you do _not_ cross. Is that clear?"

Sherlock's eyes narrowed, but he still gave her a lopsided smirk all the same.

"Crystal."

Katrina let go of him, and he straightened out his jacket, looking in the mirror above the mantelpiece so he could adjust his collar too. She sat back on the edge of the desk again, glancing over at John who had watched the interaction with bated breath. He relaxed when she seemed to calm down.

"Do we have a plan though?" John asked tentatively. "Apart from wait fifteen minutes to follow you to… where it is you have to go?"

"Not really, no. This is something I have to do myself. And if it goes horribly wrong, I'm glad it's the weekend," she said, amusing herself with the addendum at the end there. "It'd be awfully tragic to die in the middle of the working week, wouldn't it?"

"That's… cheerful…" John really didn't know how to react to her blase attitude. Sherlock snorted, and he shared a look with the woman - somehow, they were on the same page. It was a level of bizarre that John didn't understand.

Meanwhile, Katrina had gone to get her coat and was searching through the pockets for something - she pulled out a debit card and her oyster card a few moments later, triumphant.

"Sometimes, I do have common sense," she announced. "Drunk me has a tendency to not put these back in my purse. Means I can get food without having to take a bag with me, like now."

"You're hungry?"

"Yes. It's been a long morning and I'm pretty certain your bread was off - I was desperate though."

"Again, how are you a functioning adult?" John repeated his earlier statement.

Katrina scoffed as she now pulled on her coat. "John, I'm twenty-seven years old. I'm not an adult in the slightest. You two should probably follow me around today. Might make things easier."

She left without another word after that, and the two men rushed to go put their things on and do exactly as she had said. Katrina was right; it would make the rest of today easier, particularly if Moriarty was keeping an eye on her, or had bugged her in some other way.

Her routine about central London at this time of day could be considered interesting or odd to say the least. There as a Pret along Baker Street which she headed into to get a sandwich, which she happily ate while walking the long way back down to Oxford Street. She seemed surprised to find a pair of tangled earphones in one of her pockets, so she ended up listening to music and blocking out the noise of London.

It was obvious that she was bored, trying to bide her time until the meeting with Moriarty - the amount of times she wandered in and out of shops aimlessly was getting on Sherlock's nerves; John was being a little more patient. They never directly followed her in unless she was longer than fifteen minutes and they hadn't seen her come out again. That only happened on two occasions.

HMV near Bond Street tube station. Katrina was taking her time in browsing various films and television shows, before deciding to have a look at headphones. Sherlock and John both glanced at each other in bemusement as she bought three different pairs of them. As she walked past them on the way out, she was texting someone quite frantically - they wondered who it could be.

The journey continued.

She dipped into H&M at the Oxford Circus roundabout, coming out some few minutes later with a a shoulder bag of some kind. She placed her purchases from HMV into there, and carried on towards Muji, where she came out with a small cheap notebook and some pens which went into her coat pocket.

"What is she up to?" John asked Sherlock. "She looks a bit suspect."

"I'm sure we'll find out soon enough," the detective replied wryly.

They followed her to Wardour Street, which she wandered down for quite some time without heading into any other shop or establishment until she reached a Starbucks. The two men followed suit and got a coffee each as she did, sitting at a nearby table to her.

Katrina then pulled out the notebook and scribbled down something before happily and slowly enjoying her beverage, taking the prescribed painkillers the doctor in A&E had given to her. That made John groan - why would anyone sensible take their pills with caffeine?!

Sherlock kept an eye on the time. It was coming up to five o'clock by the time Katrina decided to up and leave, but not before stopping by their table.

"You guys are doing pretty good," she remarked, sitting next to Sherlock.

"It's our job," he replied, rolling his eyes. "What's wrong?"

Katrina placed a note on the table.

"I'll see you soon."

She winked and left.

 _Bethnal Green tube station in an hour. I have to go do something first, don't follow._

"Probably got something to do with the headphones?" John offered.

"It is. She pickpocketed me," Sherlock huffed.

"I'm sorry, what?!"

"She took my Swiss Army Knife - I think she's dismantling the headphones for parts and giving them to someone. That's why she spent so long in HMV."

John shook his head, not even sure how to react to that. "She's… something."

* * *

Katrina had never liked Hackney. Granted, Victoria Park was beautiful but anything else was too hipster or too rowdy for her liking. How lovely of Moriarty to invite her there to meet, in some East End abandoned building that she was worried about getting mugged on the way to. She followed google maps to get where she needed to go, annoyed about the fact the sun had set and it was getting too dark for her liking.

What a time to be a woman walking alone at night. She ended up taking out one earphone so that she could at least hear the rest of her surroundings while heading down the darkened alleyway that led to the back of the building she had to head into. The only thing that eased her was the fact Sherlock and John were some ways behind her.

It didn't shock her that it was a decrepit house. The back gate was rusted and unbolted, so she had easy access to it. She had to put on her phone torch to accommodate for the lack of light there now was as she entered the back door of the house.

Investigating the downstairs section, there was nobody there, so she headed up.

There was a gentle glow coming from one of the rooms, under a closed door. Katrina gently pushed it open and turned off her phone light to find a singular lamp plugged into the wall of the room - which itself was quite a large space - and a suited man standing towards the front of it by a window.

He turned and gave her a wicked grin.

"Moriarty," she said, turning off her music, pocketing her phone and earphones. "Pleasure."

"I believe the pleasure is all mine," he said. "Apologies about Seb last night, didn't mean for him to get so… _violent_. But he _is_ very good when you pay him _very well_ , so… oopsie?"

"You don't mind I'm of the opinion we should just get this over with?" Katrina said, pulling the necklace off and holding it up. "You _really_ didn't need to kill my ex for this."

"Oh, but I did - it's more fun like that." Moriarty sounded far too charming to be talking about murder in such a casual way. It unnerved Katrina to no end. Regardless, she tossed him the necklace and he caught it seamlessly.

"What do you need that for?"

Moriarty tapped the side of his nose as he pocketed the necklace.. "That's for me to know and you to find out."

"Makes sense…"

"How's Sherlock by the way?"

Katrina raised a disinterested eyebrow. "He's fine. Annoying, but fine. Why?"

Moriarty shrugged. "Thought I'd ask, since he's on his way here."

She blanched, her face going a little paler. He laughed and stepped towards her until they were nose to nose.

"You can't hide anything from me, little cat," he whispered in her ear.

As Moriarty walked away, Katrina was faced with Sebastian Moran on the opposite end of the room aiming a gun at her. She barely had time to react before he fired it and there was an incredibly sharp pain in her side, the force of it enough to knock her to the floor.

They left her there to bleed out, unable to make a sound as she was in too much shock.

* * *

 **Don't worry too much, she's not going to die! Otherwise there would literally be no point to this. Anyway this is the end of the first arc, gonna have some filler chapters before moving onto the next mystery.**

 **Comment?**

 **-OL**


	9. The Diamond Girl: Finale

Katrina was high as a kite when she woke up, and was quite frankly thankful for it. The morphine did enough to dampen the pain from the bullet wound, but not enough for her to ignore the fact she could feel the stitches in her side. The slightest movement would make her aware of their presence in her body. She very clumsily lifted a hand to her face so she could pull away the oxygen mask from it. When she found herself to uncoordinated to do so, she groaned in annoyance.

That was what made Sherlock pay attention to her. He'd been half asleep in a chair near her bed all night and he jolted to life when Katrina made that little whining noise. Seeing what she was trying to do, he removed the mask for her. He then brought the chair closer to the bed and sat back down. Her confused frown nearly made him laugh - he had to stifle it back.

Sherlock then cleared his throat. "How are you feeling?" That was social protocol, wasn't it? Asking someone how they felt after an injury being tended to, even though the answer was obvious?

"Weird," Katrina muttered in response after some careful consideration. "What did I smoke to get like this?"

God, it was getting really hard not to laugh, because he knew it was starting to show on his face, not that the mildly delirious woman could tell. Before he could say anything, John walked in with two cups of coffee, looking rather tired himself. He wordlessly handed one to Sherlock and pulled up the other chair, a little more upbeat after noticing Katrina was awake.

"John," the woman said seriously. "What did I smoke? Sherlock won't answer."

He was rather bemused by the question at first, but upon seeing Sherlock hiding his mouth behind his hand, realised what was going on.

"You were shot, Katrina, remember?" he began to explain, finding it difficult to keep a smile off his face. "And you've been given a lot of morphine."

She blinked a few times before the cogs in her brain finally worked to remember the events of the past day. "Shit." Katrina seemed to sober up at that point too, and it stopped the situation from being funny. "He - Moriarty - he knew. About you two."

"We figured that out when we found you alone and bleeding out in the house," Sherlock said. "You didn't say anything to alert him to us, did you?"

Katrina scowled at him briefly, not having the energy to maintain such a facial expression. "No. Of course not. He was… probably one step ahead."

"He always is," Sherlock mused, not exactly happy with that prospect.

"So what happened? How comes I'm not dead?"

"Well…"

* * *

 _The two men had almost lost track of Katrina. Almost. The sun had set and it was winter, after all, it got dark quicker than anyone could blink. Either way, they managed to catch her trail as they wandered in silence through Hackney. They had to stay far enough away from her so that nobody would suspect._

 _When she took an abrupt turn down an alley, they waited a few moments before carrying on after her. Obviously, they could have lost her there and then, but there was only one set of lights on out of all the houses down that particular area._

 _They patiently waited outside the back gate until an opportune moment._

 _It was just a shame that the opportune moment was when a gunshot sounded out._

 _The pair looked at each other with wide eyes and ran through the back gate and up into the house. The front door was slammed shut as they entered; Sherlock gritted his teeth upon realising they had just missed Moriarty._

 _He and John ran upstairs and into the room with the lights on to find Katrina half conscious on the floor and bleeding out._

 _"Call an ambulance," John said, immediately dropping to his knees next to Katrina and pressing his hands over her wound. She groaned and tried to bat him away, but didn't really have it in her to do anything. Sherlock did as the doctor requested, and then got on his knees next to Katrina as well._

 _"This… really hurts…" she whispered, managing to grab onto Sherlock's arm. He let her take hold of it, even if he did tense up._

 _"Help's on its way," he replied steadily. "You'll be fine."_

 _"Hmm mm…"_

 _Sherlock and John exchanged a worried glance. "Keep talking to her," John muttered._

 _"The good news is you're not dead," Sherlock told her frankly. Her lips twitched upwards in an awkward, tired half smile._

 _"Stay," she told him. "Please?"_

 _That was… interesting. Nobody had wanted his company before._

 _Sherlock nodded all the same._

* * *

Katrina was silent for a moment.

"I see. Well. Thank you."

"You're very calm for someone who had a death threat hanging above them and it nearly followed through," John pointed out. Katrina shrugged.

"There are worse ways to go."

Sherlock hummed in agreement, while John looked between the pair absolutely astounded. Of course they were going to be in agreement over something like that - she was an intriguing person, with a bizarre talent that neither of them had seen the full extent of.

What was stranger was how they weren't at each other's throats, as most people would be with Sherlock. It made John wonder what end of the spectrum Katrina was even on to not be constantly yelling at Sherlock whenever he made an offhand comment.

Before John could even say anything, the door flung open and a woman came bounding in. She looked like a younger version of Katrina, except her hair was leaning more towards auburn than dark brown. She still had the same blue eyes, but her features were far softer.

"Oh no, not you," Katrina murmured, sinking back into her pillow. "Who called you?"

Completely ignoring Sherlock and John, the woman came to sit on the edge of Katrina's bed. "You got shot?!"

"And now I wish I actually had died," she sighed deeply, and peered round the woman at the two men. "Which one of you did this?"

"We didn't," Sherlock said, and held up three fingers. "Scouts honour."

John scoffed. "Yeah, like you were ever a scout."

"So it was the hospital, then. Sherlock, John, meet my younger sister Isabel."

"How did I manage to miss the fact you had a sister?" Sherlock muttered under his breath to himself. "How?!"

Everyone was staring at him get progressively more annoyed with himself; it was amusing, to say the least, and it most definitely provided some form of entertainment for Katrina. She needed something fun right now, especially with Isabel in the room.

"He's weird," Isabel then stated.

Katrina coughed to cover up a laugh. "Now there's something we can agree on, finally."

Sherlock scowled at her, but she merely shrugged it off. Not really the time to get into a stupid argument with him, not when her even more annoying little sister was there.

"Isabel, why are you here?" she asked the offending party.

"They called me here because I'm your next of kin - it was lucky I was in London, actually."

Katrina sighed. "Well, I don't particularly want you here, so you didn't have to come. Go back to whatever you were up to, and we can go back to the regular Christmas cards and birthday cards without having to see each other again."

Isabel's eyebrows shot into her hairline, and she stood up. "Gosh, you were always so ungrateful."

"No, you were just handed everything on a plate because you were more normal," she replied ,a dark look crossing her eyes. That glare alone was enough for Isabel to huff and make a hasty exit. The two men turned to look at her, gobsmacked with the outcome of that interaction.

"Well… siblings are difficult," John eventually said.

"Don't we all know it," Sherlock agreed.

Katrina glanced between the pair of them, a smile beginning to form on her face. Perhaps it wouldn't be so strange to still maintain contact with them; after all, they seemed to have at least one thing in common that a friendship could potentially grow from there.

"So… you guys wouldn't mind helping me sort out my flat, would you?" she threw the question at them tentatively. Sherlock rolled his eyes and was about to open his mouth to make a sarcastic remark, but John stopped him in his tracks.

"Katrina, I think it's the least we could do."

* * *

 **I know it's been months, I've been way too invested in my True Blood fic. But here's a short chapter anyway, hoping to get the ball rolling on this again soon. :)**

 **Comment?**

 **-OL**


	10. Secret Interests

It took a few weeks, but soon enough Katrina was fully recovered and her flat had been tidied up. She most definitely had Sherlock and John to thank for the latter part of that, as well as her work buddies in the tech department too. Oddly enough, she kept it from them the circumstances of her being shot, making an offhand comment about being in the wrong place at the wrong time.

She was lucky that they believed it. Only Sherlock and John knew the truth; besides, she didn't want to be worrying anyone at work about that.

There was another thing too, which she didn't want Sherlock or John to know about. It was the dreams she kept having about Moran breaking into her flat. Katrina was acutely aware of the fact that lying awake at night for two hours straight in bed after waking up from a bad dream wasn't exactly healthy, and was most definitely not a good idea to keep to herself; regardless, she did it all the same.

Katrina considered herself lucky that it didn't affect her day to day life, as she was used to not sleeping much in general - she'd never been good at sleeping, and it's not like the dreams would last forever. They were intense the first few days, yes, but they started to fade away and become less frequent. She was good at stopping herself from going to a too dark place along with it as well.

It was only when she decided to visit Sherlock and John - instead of communicating to them via text - that did she realise her discomfort was written all over her face.

John wasn't in, so it was just her and Sherlock until he got back. She wanted to express her gratitude to them at the same time so she didn't have to put the detective through social formalities more than once. Katrina had a feeling he wouldn't like that.

So while he was on his laptop, she picked up the newspaper and read it while perched on the sofa. There was nothing particularly interesting going on, but Katrina assumed Sherlock would always find something to pick out and pick apart.

"Something's bothering you," he then said rather suddenly, making her jump. Her gaze flickered to him over the top of the newspaper to find he was scrutinising her rather intensely.

"I'm fine," she said tersely.

Sherlock harrumphed and went back to typing away. Katrina tried to concentrate on the newspaper but found her cheeks going pink as she could feel him keeping glancing back over at her.

"Stop it," she warned him.

"Trauma presents itself in many ways, Katrina, nothing to be ashamed of but maybe stop trying to hide it. Lying doesn't suit you."

"You're right, lying doesn't suit me," she agreed, folding up the newspaper and tossing it down onto the coffee table, crossing one leg over the other as she did so. "But there are certain things that aren't your concern, Sherlock."

"Then why are you here?"

"I came here to actually tell you and John thank you in person, but he's not here yet. I was bored of texting the both of you," she started off. "And… what happens now? Are we meant to go our separate ways? Do I pay you despite the fact that you provided me your services without my asking? You wouldn't allow a normal client to text you updates of their injury, would you?"

Sherlock's eyes narrowed, and Katrina knew she had got him there.

"Go on then. Why do you both still talk to me?"

"You intrigue me."

"How so?"

"You have secrets - everyone does - but they're harder to figure out than most other people. You're too good for your current job, I know that much, and you're clever. Not many people who rely on their emotions are usually clever."

Now it was her turn to scowl at him, but he ignored it and carried on talking.

"Except I'm missing something about you, and that doesn't happen with normal people - you're not normal."

"Is that meant to be a compliment?" she teased him with a now raised eyebrow.

Sherlock scoffed. "I don't do compliments, Katrina, and most people don't take the words 'not normal' as a compliment. So why do you?"

"You didn't say it in a horrible way. I'm taking the fact you can't figure me out as a compliment. Having some mystery left in the world could do you some good."

A half smile snuck it's way onto Sherlock's face ever so briefly, but it was whisked away by the fact he noticed someone standing in the doorway - a someone he was rarely keen on visiting.

"You've made a friend," said the person in the doorway, catching Katrina's attention too.

"No, Mycroft, I haven't," Sherlock sighed, making the woman roll her eyes.

"Well, one can hope."

"Maybe don't hope too much."

Katrina's eyes were darting back and forth between Sherlock and the suited man with the umbrella, and it made her wonder what kind of mother would name her child "Mycroft."

"And a woman of all the people for you to be talking to. Perhaps I was mistaken in thinking that sex alarmed you," Mycroft said as he waltzed over to the red armchair and settling down in it.

"Said woman is still present and has ears perfectly capable of hearing," Katrina said coolly, grabbing the attention of both men. "Can I have an explanation?"

"Katrina, this is my brother Mycroft. Mycroft, this is… an ex-client, Katrina Jenkins," Sherlock said.

The same person who named Sherlock also named Mycroft. That made perfect sense to her.

"Of course. The _Diamond Girl_ ," Mycroft mused as he gave Katrina a calculating once over; something that seemed more intense than when Sherlock did it.

"The _what_ now?" Katrina's eyebrows went up into her hairline.

"Diamond Girl. John's title for the case on his blog - do you not keep up?" Sherlock replied.

"Normally I do, but I've been…"

"Yes?"

"Distracted."

"So there is something bothering you."

"Not that it's any of your business."

"Then why are you here? Clearly not just for a thank you." Sherlock slammed the lid of his laptop down and rested his fingertips under his chin. "Nor to find out what happens next."

Katrina was chewing on the inside of her lip, debating the best way to ask the question. She didn't want to alarm Sherlock, but she didn't want to make Mycroft too privy to any information. Either way, the other Holmes was watching her with a strange curiosity that she wasn't sure how she felt about it.

"Will he come after me again?" she asked Sherlock quietly, who tilted his head to the side ever so slightly.

"Why are you asking me this now instead of two, nearly three weeks ago?"

"Answer the question," she told him in a dangerously low voice along with a fiery look. She ignored Mycroft completely and therefore didn't see how his curiosity was now piqued; he had turned in the chair ever so slightly to face her, to watch her more closely.

"He shouldn't. If he does, then that means you're of use to him. Now answer my question."

"I've had… bad dreams about Moran breaking into my flat," she admitted quietly, after a moment of so. "Not so frequent now, but a few weeks ago… definitely frequent. I wanted to wait until my mind had calmed down, so to speak."

"Good call."

"Why would Miss Jenkins be of use to Moriarty?" Mycroft then piped up.

"I mentioned Moran, not Moriarty," she said carefully, frowning as she looked over him.

Mycroft sighed, and Sherlock elected to speak before his older brother could.

"Mycroft claims to be cleverer than me. And he's practically the British government, so people like Moran and Moriarty are one his radar. Plus they work together an awful lot."

"I occupy a minor position-"

"If Mr Holmes is so clever," Katrina cut across him, "then surely he would know why I would be of use to Moriarty. If I were to be of use to Moriarty."

"I wasn't aware of you being on my brother's radar until today, Miss Jenkins," Mycroft said calmly. "Why would Moriarty want to come after you twice? What do you have that he needs?"

"It was a hypothetical question-"

"As is mine," Mycroft said rather darkly. Now it was Sherlock's turn to watch a back forth, one that he could see was beginning to aggravate Katrina. Her jaw had become taut, and he could see the restraint in her holding back an intense anger.

He didn't need to know emotions or be a detective to figure out that one.

"Find out for yourself," she ended up saying and leaning back on the sofa in a deflated manner. "Although, actually, I did have that diamond he wanted. That's it. So if he came for me for anything else I have - you'll just have to find out for yourself."

"That's why I'm here, actually," Mycroft quirked an eyebrow at Katrina, causing both her and Sherlock to be shocked.

"Stop spying on people who associate with me for a few minutes," Sherlock grumbled.

"Oddly enough, I'm with Sherlock on that one," Katrina agreed, standing up and heading over to Mycroft, squaring up to him. "If you want to talk to me, you ask for me. You don't stalk me to your brother's flat, British government or not."

There was a tense silence hanging in the air between the pair; Sherlock was almost ready to jump out of his chair to pull Katrina away from Mycroft, tell her that he wasn't worth threatening because he'd just do it far worse. It was strange to see them hold each other's gaze evenly, both of their auras attempting to dominate - because Mycroft could easily do that from a chair.

Soon enough, Mycroft actually relented. His shoulders sagged - not in defeat, but more in that he was relaxing.

"Fine," he said curtly, rising to tower over Katrina, who took a fearful step back. That brought a half smirk to the older Holmes' face. "I'll be seeing you, Miss Jenkins."

Katrina didn't take her eyes off of Mycroft as he left the room and went past a rather bemused John, who entered carrying a pint of milk. He glanced back at the government official, and then at the seething woman in the flat.

"So… what did I miss? How come you're here, Katrina?"

"I came here to say thank you to you and Sherlock in person," she said, simmering down. "Apparently his older brother is fascinated by me, and I don't know. Not sure if I want to find out."

"Right…" John frowned as he headed to the kitchen to put the milk away. "Well. Avoid Mycroft as much as you can, would be my suggestion," he called back over his shoulder.

"Please, no matter how much she tries he'll probably show up at her work in a few days time," Sherlock remarked dryly.

Katrina sighed, making her way to the door. "Perfect. Just what I want." She turned back to Sherlock. "Thank you, though, for all your help. I'll see you around, I guess?"

"Possibly…"

Katrina rolled her eyes and left 221b, most definitely anticipating when she would be visited by Mycroft.


End file.
